Electronically operated remote control systems, such as garage door opener systems, home security systems, home lighting systems, gate controllers, etc., typically employ a portable, hand-held transmitter (i.e., an original transmitter) to transmit a control signal to a receiver located at the remote control system. For example, a garage door opener system typically includes a receiver located within a home owner's garage and coupled to the garage door opener. A user presses a button on the original transmitter to transmit a radio frequency signal to the receiver to activate the garage door opener to open and close a garage door. Accordingly, the receiver is tuned to the frequency of its associated original transmitter and demodulates a predetermined code programmed into both the original transmitter and the receiver for operating the garage door. To enhance security of wireless control systems, such as a garage door opener system, manufacturers commonly use encryption technology to encrypt the radio frequency signal sent from a transmitter to a receiver. One such encryption method is a rolling code system, wherein each digital message sent from the transmitter to the receiver has a different code from the previous digital message.
As an alternative to a portable, hand-held original transmitter, a trainable transmitter or transceiver may be provided in a vehicle for use with remote control systems. A trainable transmitter is configurable by a user to activate one or more of a plurality of different remote control system receivers using different radio frequency messages. A user may train the trainable transmitter to an existing original transmitter by holding the two transmitters in close range and pressing buttons on the original transmitter and the trainable transmitter. The trainable transmitter identifies the type of wireless control system associated with the original transmitter based on a radio frequency signal received from the original transmitter. For example, the trainable transmitter may identify and store the control code and RF carrier frequency of the original transmitter radio frequency control signal. In addition, the receiver of the remote control system must learn a transmitter identifier of the trainable transmitter. For systems employing a rolling code (or other encryption method), the trainable transmitter and receiver must be “synchronized” so that the counters of the trainable transmitter and the receiver begin at the same value. Accordingly, the user presses a button on the receiver to put the receiver in a training mode. A button on the trainable transmitter may then be pressed, for example, two to three times, to transmit messages so the receiver may learn the transmitter identifier, complete synchronization of the receiver and the trainable transmitter and confirm that training was successful. Once trained, the trainable transmitter may be used to transmit RF signals to control the remote control system.
As mentioned, a trainable transmitter or transceiver may be trained to one or more of a plurality of remote control systems using different radio frequency messages. Accordingly, a trainable transmitter may include multiple channels where each channel may be trained to a different radio frequency control signal. During manufacture of a trainable transmitter, a manufacturer may program the channels of the trainable transmitter with default mode data (e.g., a default control signal or rolling code) and an appropriate frequency or frequencies so that the operation of the trainable transmitter may be tested after final assembly. The default mode data may be, for example, generic control data (fixed or rolling code) or control data for a particular type of remote control system (e.g., a fixed code garage door opener system) that is pre-stored in the trainable transmitter for testing of the trainable transmitter. In addition, an automobile manufacturer may wish to test the trainable transmitter during vehicle manufacture using the default mode data. The trainable transmitter is tested by transmitting the default mode data to a default mode receiver (e.g., a generic receiver or an appropriate receiver corresponding to the pre-stored control data) in close range to the trainable transmitter. If the channels are not cleared before shipping the trainable transmitter (e.g., either to an automobile OEM or in a vehicle to a customer), the training process for a trainable transmitter often includes a first step of having the user clear each channel of the trainable transmitter of the default mode data before placing the trainable transmitter in a training mode to be trained to the user's remote control system. This additional step may be cumbersome and inconvenient for a user. In addition, if the user does not clear the channels of default data, the trainable transmitter may not train properly.